2,850 research outputs found
Blue biotechnology: oil bioremediation using hydrocarbon-degrading bacteria immobilized on biodegradable membranes
A novel bioremediation system to clean up oil contaminated water was developed combining hydrocarbon (HC) degrading bacteria immobilized and polylactic acid (PLA) or polycaprolactone (PCL) membranes prepared by electrospinning. The bioremediation efficiency was tested on crude oil using highly performant HC degrading bacterial strains isolated from marine and soil environments. The membrane morphology, the microbial adhesion and proliferation were evaluated using scanning electron microscopy (SEM). The SEM analysis highlighted that the fibers of the electrospun mats were in nanoscale with a similar diameter size distribution. The electrospun membranes exhibited high oil absorption capacity (q): approximately q = 40 g/g for PLA and q = 20 g/g for PCL. The bacterial strains were able to attach to the PLA and PCL membranes after 48h, reaching high proliferation and biofilm formation within the whole structure in 5 days. The biodegradation efficiency of the bacteria-membrane systems was tested by GC-FID analysis and compared with planktonic cells after 5 and 10 days incubation. The bacterial immobilization is a promoting factor for biodegradation and a new tool to be developed for bioremediation of aquatic systems
Blue biotechnology: enhancement of bioremediation using bacterial biofilms on biodegradable scaffolds
Petroleum hydrocarbons are still the most threatening environmental pollutants. A promising non invasive and low-cost technology for the treatment of contaminated sites is based on bioremediation by biodegrading microorganism endowed with catabolic ability towards oil and derivatives. New methods are needed to enhance and optimize natural biodegradation, such as the immobilization of hydrocarbons degraders in many types of supports. We developed a scaffold-bacteria bioremediation system to clean up oil contamination based on degradable 3D scaffolds. The polycaprolactone component is biodegradable, produced in the melt, i.e. at low cost and without the use of toxic solvents. The biofilm is made of highly performing HC-degrading bacteria such as the marine hydrocarbonoclastic bacteria (HCB) (1) or solid n-alkane degrading Actinobacteria (2, 3). The bacterial biofilm is observed within the whole structure of scaffold using scanning electron microscopy. The bioremediation efficiency of such systems was tested on crude oil by GC-FID analysis and compared whit planktonic cells. The biofilms formation was a promoting factor for biodegradation showing hydrocarbon removal up to 70% and 15% more in respect to the planktonic cells. Increasing availability of the contaminants and a better interaction between the hydrophobic substrate and the bacterial cells resulted in developing the degradation rate. Biofilm-mediated bioremediation is a new tool to be developed for bioremediation of acquatic system
The Glycolytic Pathway as a Target for Novel Onco-Immunology Therapies in Pancreatic Cancer
Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal forms of human cancer, characterized by unrestrained progression, invasiveness and treatment resistance. To date, there are limited curative options, with surgical resection as the only effective strategy, hence the urgent need to discover novel therapies. A platform of onco-immunology targets is represented by molecules that play a role in the reprogrammed cellular metabolism as one hallmark of cancer. Due to the hypoxic tumor microenvironment (TME), PDA cells display an altered glucose metabolism—resulting in its increased uptake—and a higher glycolytic rate, which leads to lactate accumulation and them acting as fuel for cancer cells. The consequent acidification of the TME results in immunosuppression, which impairs the antitumor immunity. This review analyzes the genetic background and the emerging glycolytic enzymes that are involved in tumor progression, development and metastasis, and how this represents feasible therapeutic targets to counteract PDA. In particular, as the overexpressed or mutated glycolytic enzymes stimulate both humoral and cellular immune responses, we will discuss their possible exploitation as immunological targets in anti-PDA therapeutic strategies
Clinical course and prognostic factors of hepatorenal syndrome: A retrospective single-center cohort study
AIM: To investigate clinical and biochemical features of hepatorenal syndrome (HRS), to assess short and long-term survival evaluating potential predictors of early mortality. METHODS: Sixty-two patients with liver cirrhosis and renal failure, defined as a serum creatinine value > 1.5 mg/dL on at least two measurements within 48 h, admitted to our tertiary referral Unit from 2001 to 201, were retrospectively reviewed. Among them, 33 patients (53.2%) fulfilled the revised criteria of the International Ascites Club for the diagnosis of HRS. Twenty-eight patients were treated with combinations of terlipressin and albumin, two with dopamine and albumin, and three with albumin alone. No patients were suitable for liver transplantation. Complete response was defined as normalization of creatinine levels to less than 1.5 mg/dL, partial response as a decrease of at least 50% but not to less than 1.5 mg/dL, no response as no reduction in creatinine or a decrease of less 50% compared to pre-treatment values. All of the patients were followed up for at least 1 year until January 2013. RESULTS: HRS type 1 was diagnosed in 15 patients (45.5%). Hepatitis C virus infection was the primary etiology (69.6%), followed by alcohol (15.2%), and cryptogenesis (15.2%). Complete response to therapy was obtained in only 3 cases (9.1%) and partial response in 7 patients (21.2%). Median survival was 30 d (range: 10-274) without significant differences between type 1 and type 2 HRS. By univariate analysis, Child-Pugh class C (P = 0.009), presence of hepatocellular carcinoma (P = 0.04), low serum sodium (P = 0.02), high bilirubin values (P = 0.009) and high Model for End-stage Liver Disease (MELD) score (P = 0.03) were predictive factors of 30-d mortality. By multivariate analysis, only serum sodium < 132 mEq/L (OR = 31.39; P = 0.02) and MELD score > 27 (OR = 18.72; P = 0.01) were independently associated with a survival of less than one month. CONCLUSION: HRS still has a poor prognosis, even when vasoactive drug therapies are extensively used
Ultrastructural Characterization of the Lower Motor System in a Mouse Model of Krabbe Disease
Krabbe disease (KD) is a neurodegenerative disorder caused by the lack of β- galactosylceramidase enzymatic activity and by widespread accumulation of the cytotoxic galactosyl-sphingosine in neuronal, myelinating and endothelial cells. Despite the wide use of Twitcher mice as experimental model for KD, the ultrastructure of this model is partial and mainly addressing peripheral nerves. More details are requested to elucidate the basis of the motor defects, which are the first to appear during KD onset. Here we use transmission electron microscopy (TEM) to focus on the alterations produced by KD in the lower motor system at postnatal day 15 (P15), a nearly asymptomatic stage, and in the juvenile P30 mouse. We find mild effects on motorneuron soma, severe ones on sciatic nerves and very severe effects on nerve terminals and neuromuscular junctions at P30, with peripheral damage being already detectable at P15. Finally, we find that the gastrocnemius muscle undergoes atrophy and structural changes that are independent of denervation at P15. Our data further characterize the ultrastructural analysis of the KD mouse model, and support recent theories of a dying-back mechanism for neuronal degeneration, which is independent of demyelination
Association between serum heat shock proteins and gamma-delta t cells—an outdated clue or a new direction in searching for an anticancer strategy? A short report
HSPs demonstrate a strong association with gamma-delta (γδ) T cells. Most of the studies regarding interactions between the parameters were conducted in the 1990s. Despite promising results, the concept of targeting γδ T cells by HSPs seems to be a forgotten direction due to potent non-peptidic phosphoantigens rather than HSPs have been found to be the essential stimulatory components for human γδ cells. Currently, with greater knowledge of lymphocyte diversity, and more accurate diagnostic methods, we decided to study the correlation once again in the neoplas-tic condition. Twenty-one children with newly diagnosed acute lymphoblastic leukaemia (ALL) were enrolled on the study. Serum HSP90 concentrations were evaluated by an enzyme-linked immunosorbent assay (ELISA), subsets of γδ T cells (CD3+ γδ, CD3+ γδ HLA/DR+, CD4+ γδ and CD8+ γδ) by flow cytometry. We have shown statistically relevant correlations between serum HSP90 and CD3+ HLA/DR+ γδ T cells in paediatric ALL at diagnosis (R = 0.53, p < 0.05), but not after induction chemotherapy. We also have demonstrated decreased levels of both serum HSP90 and CD3+ HLA/DR+ γδ T cells before treatment, which may indirectly indicate dose-dependent unknown interaction between the parameters. The results of our study may be a good introduction to research on the association between HSPs and CD3+ HLA/DR+ γδ T cells, which could be an interesting direction for the development of anti-cancer strategies, not just for childhood ALL
Renewal processes and fluctuation analysis of molecular motor stepping
We model the dynamics of a processive or rotary molecular motor using a
renewal processes, in line with the work initiated by Svoboda, Mitra and Block.
We apply a functional technique to compute different types of multiple-time
correlation functions of the renewal process, which have applications to
bead-assay experiments performed both with processive molecular motors, such as
myosin V and kinesin, and rotary motors, such as F1-ATPase
Microturbulence studies in RFX-mod
Present-days Reversed Field Pinches (RFPs) are characterized by quasi-laminar
magnetic configurations in their core, whose boundaries feature sharp internal
transport barriers, in analogy with tokamaks and stellarators. The abatement of
magnetic chaos leads to the reduction of associated particle and heat transport
along wandering field lines. At the same time, the growth of steep temperature
gradients may trigger drift microinstabilities. In this work we summarize the
work recently done in the RFP RFX-mod in order to assess the existence and the
impact upon transport of such electrostatic and electromagnetic
microinstabilities as Ion Temperature Gradient (ITG), Trapped Electron Modes
(TEM) and microtearing modes.Comment: Work presented at the 2010 Varenna workshop "Theory of Fusion
Plasmas". To appear in Journal of Physics Conference Serie
Virus-like Particle (VLP) Vaccines for Cancer Immunotherapy
Cancer vaccines are increasingly being studied as a possible strategy to prevent and treat cancers. While several prophylactic vaccines for virus-caused cancers are approved and efficiently used worldwide, the development of therapeutic cancer vaccines needs to be further implemented. Virus-like particles (VLPs) are self-assembled protein structures that mimic native viruses or bacteriophages but lack the replicative material. VLP platforms are designed to display single or multiple antigens with a high-density pattern, which can trigger both cellular and humoral responses. The aim of this review is to provide a comprehensive overview of preventive VLP-based vaccines currently approved worldwide against HBV and HPV infections or under evaluation to prevent virus-caused cancers. Furthermore, preclinical and early clinical data on prophylactic and therapeutic VLP-based cancer vaccines were summarized with a focus on HER-2-positive breast cancer
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